EP1679470A2 - Lighting device with hollow light guide - Google Patents

Abstract

A light for room illumination has a space (5) with one or more partly reflecting walls (11), and the first wall (9) is partly transparent and has a light-decoupling zone. A linear light-refracting structure is provided on the first wall (11) and extends parallel to the light-source and has a tapering cross-section in a plane normal to the line defining it. The sides of the cross-section approximately lie in one region from 100 deg. to 130 deg. while the second wall (7) of the light transparent zone has a structure of linearly shaped light refracting elements extending parallel to the light source, and possess a tapering shape in the cross-section in one plane normal to the defining line.

Description

The invention relates to a luminaire for room lighting, in particular an interior luminaire, which has a cavity with one or more reflective walls, which has a first wall, which is translucent at least on a partial area and has a light coupling-out area of the cavity, a second, at least partially translucent wall, and having a third wall opposite the first wall which is wholly or partially reflective, the lamp having one or more lamps disposed outside the cavity and coupling light into the cavity via the second wall.

Such luminaires are known, for example, from US Pat. No. 4,059,755 or EP 1 111 298 A1. Recent developments are aimed at creating a shielding by light-refracting structures on translucent surfaces, which have hitherto been brought about by screens or opaque reflectors which prevent the emission of light in certain directions.

Shielding refers to a light emission behavior of a luminaire in lighting technology in which above a certain critical angle to the vertical, typically in the range of 50 ° to 80 °, in certain spatial planes, for example in the C-planes defined in DIN EN 13032-1 or in the C-planes corresponding planes perpendicular to the light exit opening of the luminaire, the average luminance is below a threshold, which is set differently in different standards and can be 1000 cd / m ² , 500 cd / m ² or 200 cd / m ² , In many cases, no specific limit value for the luminance is specified, but only required that it should not come to a glare due to light that exits above certain angles to the vertical in space, based on certain spatial levels.

It is known that a shielding in the plane transverse to the longitudinal direction of the prisms can be produced by a suitable embodiment of straight line-shaped prisms, which have a triangular shape in cross section. This is described in particular in EP 1 111 298 A1. It has been believed that such elongated prisms create a shield substantially only in the plane transverse to its longitudinal direction. Accordingly, it has been proposed to provide on the light exit side of the cavity prisms, which extend parallel to the lamp axis and to provide on the Lichteinkoppelseite prisms which are perpendicular to the lamp axis.

Although the concept known from EP 1 111 298 A1 has basically proven itself. A disadvantage, however, is that the length over which the prisms extend at the Lichteinkoppelseite is relatively short. Short line prism structures that extend in the direction transverse to their longitudinal direction over a distance that is approximately the length of a typical interior light or a typical fluorescent tube, are relatively expensive in production. Due to the short length of the prisms, edge effects also play a much greater role than with comparatively long structures. Likewise, imperfections, which mainly occur in the peripheral areas, have a stronger effect.

A construction in which prisms parallel to each other at the light input side and at the light exit side of a cavity are provided is described in US Pat. No. 4,059,755. There, too, it is assumed that the light intensity distribution curve is designed by these prisms only in the plane perpendicular to its longitudinal axis.

It is, starting from EP 1 111 298 A1, the object of the invention to provide a luminaire of the type described above, which is subject to at least two different levels of glare limitation due to refraction and which is easier to manufacture.

This object is achieved by a luminaire for room lighting, in particular an interior light, with a cavity having one or more at least partially reflecting walls, which has a first wall which is translucent at least on a partial area and a Lichtauskoppelbereich of the cavity and in the Lichtauskoppelbereich has a structure of line-shaped refractive elements at least on one side, a second, at least partially transparent wall and a third wall opposite the first wall, which is formed completely or partially reflecting at least on a partial area, and with at least one line-shaped light source which outside the cavity is arranged so that light from these light sources is coupled via the second wall into the cavity and is coupled out via the light outcoupling region of the cavity in the first wall of the cavity the light coupled out via the light extraction region is emitted at a light exit surface of the luminaire, which is characterized in that the linear refractive structures on the first wall are parallel to the or at least one of the light sources and has a tapered cross section in a plane perpendicular to the light source they have a defining line, the angle between two straight lines, which form or approximate the two opposite flanks of the cross-section is in a range of 100 ° to 130 °, preferably 110 ° to 128 ° and in particular 116 °, while the second wall in the light-transmissive region, via which light of the lamps in is coupled to the cavity has a structure of line-shaped refractive elements which are parallel to the light source and in a cross section in a plane perpendicular to the line defining it have a tapered shape, wherein the angle between two straight lines which the two each other form or approximate opposite flanks of the cross section, in a range of 80 ° to 100 °, in particular 80 ° to 95 °.

The angle between the two said straight lines is understood to mean the angle at which the two lines or the straight lines which extend these two straight lines intersect.

Cross-sectional shapes in which the said lines form the flanks of the cross section are, for example, the shape of a triangle or a trapezium. However, the invention can also provide that the cross section has a triangle or a trapezoidal shape, in which the flanks and / or the tip, for example, consist of a curved line or a polygon. For the determination of straight lines which approximate the flanks of such a cross section, it is possible, for example, to specify the optimization criterion that the area between the flank and the line which is to approximate this flank is minimal or that the deviation of the flank from the line approximating it, relative to an axis perpendicular to the approximating line, integrated over the entire length of the approximating line or the region of the flank, is minimal, in the latter case deviations from the approximating line in different directions being positive or negative. Other geometric approximation methods may also be used, for example the approximation by two tangents to the flanks of the cross section, which have the greatest slope of all tangents, or the approximation by a triangle or a trapezium with the smallest surface area, which accommodates the cross section. Ultimately, it is important that the structures whose elements in the said cross-section have flanks not by a simple straight lines are formed, a comparable refractive behavior, in particular with regard to the formation of a shield, as the structures show, the elements in cross section have flanks in the form of a straight line.

It has surprisingly been found that, unlike this, for example, was still required in EP 1 111 290 A1, not only with refractive structures, which are oriented differently with respect to the longitudinal axis of the lamp, can bring about a shield in at least two levels, but also through structures that are oriented in the same direction. If the angle between said lines in the specified range, can be in the usual translucent materials having a refractive index in the range of 1.4 to 1.6, a shield in at least two mutually perpendicular planes, for example in longitudinal and Transverse direction of the luminaire, reach. The above-mentioned angle ranges lead to the material polymethyl methacrylate (PMMA) to particularly good results; for other materials similarly good properties result for an angular range, which is determined by the condition that the same refractive behavior is given, which results in PMMA for the angular range given above.

The line-shaped light sources may be light sources whose three-dimensional shape results from translating a base area along a predetermined line and / or those light sources having a strip-shaped light emitting surface. In the first category in particular straight or annular fluorescent lamps, in the second example, strip-like arrangements of point light sources, such as light-emitting diodes, or strip-shaped electroluminescent films. In the case of a straight light source, the straight line-shaped structures on the first and second walls follow a straight line, while, for example, in the case of an annular light source, the linear refractive structures on the first and second walls would follow a circle. The above-mentioned cross section would then in the first case a cross section perpendicular to the said straight line and in the second case a radial cross section.

The invention may provide that the refractive structures on the first and second walls in a cross section perpendicular to the line defining them, in particular perpendicular to their longitudinal direction, have a triangular shape, wherein the angle enclosed by the two legs at the free end of the structures for the structures on the first wall in a range of 100 ° to 130 ° and for the structures on the second wall in a range of 80 ° to 100 °.

The refractive structures may also have a different shape in cross-section, in particular a trapezoidal shape. In the latter case, the indicated angle corresponds to the angle between the two opposing non-parallel sides of the trapezoid.

The invention also provides a luminaire for illuminating interior spaces with a cavity having one or more at least partially reflecting walls, wherein the cavity has a first wall which is translucent at least on a partial area and has a light outcoupling area of the cavity and in the light outcoupling area at least one side has a structure of linear refractive elements, a second, at least partially translucent wall and the first wall opposite third wall which is formed wholly or partially reflective at least on a partial area, and with at least one, preferably linear light source, the is arranged outside the cavity so that light from the light source is coupled via the second wall into the cavity, which is characterized in that the second wall in the light-transmissive region has a structure of refractive Ele having each having the shape of a cone or a truncated cone.

The invention may provide that the cone or a cone, which results from a continuation of said truncated cone, at its tip has an opening angle of 100 ° to 128 °, in particular 110 °.

Again, the preferred angular ranges for the material PMMA are given, with a preferred angle for other materials resulting from the condition that the same refractive behavior as in the material PMMA should be given in the above-mentioned angle range.

According to a preferred embodiment, the structure of line-shaped refractive elements of the first wall is parallel to said light source.

The invention may provide that the cones or truncated cones are arranged hexagonally.

Under a cone is understood to mean any body whose lateral surface by the movement of a straight line through a fixed point that slides along a guide curve, and bodies that have approximately such a lateral surface. Accordingly, a truncated cone is understood to mean a body which corresponds to a cone in the sense of the invention which is cut off at its tip along a plane which does not intersect the base surface and at most touches in an edge point, in particular such bodies in which the tip of the Cone is cut along a plane parallel to the base.

The above-mentioned guide curve may in particular be a circle, so that corresponding cones have substantially a circular cone shape. However, it can also be a polygon, so that the element has the shape of a pyramid, in particular the shape of a six- or eight-sided pyramid.

According to a presently preferred embodiment of the invention, the elements have the shape of a circular cone, which is laterally cut off in the region of its base in the form of a hexagon. More specifically, the shape of these elements is generated from a cone cut along six planes that are parallel to the cone axis and that together enclose a space that is in the shape of a hexagonal cylinder whose cylinder axis is parallel to the cone axis. Such an element thus has at the end remote from the tip of a hexagonal in plan view circumference and from a certain distance from the tip to the tip in a cross section perpendicular to the axis of symmetry the shape of a circle. Said hexagonal design makes it possible to arrange these elements in the manner of a hexagonal closest packing without gap, while they have a rotational symmetry with respect to the cone axis towards their tip and thus show the same refractive behavior homogeneously in all directions in this region.

Alternatively, it can also be provided that the elements have the shape of a pyramid with hexagonal base and or have a different basic shape than that of a circular cone and are cut along the surfaces of a hexagon in the vicinity of its base.

According to another embodiment, it is also possible to use elements which have a polyhedral area other than a hexagon as the base area or which are laterally cut off in accordance with such a polygon, in particular elements with an octagonal base being considered.

In principle, it would also be conceivable, for example in the case of elements in the form of exact circular cones, to leave a gap between the elements, as is the case with the dense arrangement of circles in a plane.

The invention may provide for a hexagonal arrangement of the elements that the radius of the hexagon between two opposite corners 1 mm and the corresponding diameter is 2 mm.

The invention may provide that the second wall is inclined to the first wall, wherein the angle between the first and second walls may be less than or equal to 150 °, in particular less than 90 °. Preferably, this angle is in a range of 30 ° to 60 ° and may have a value of 40 °, in particular in preferred embodiments.

However, the second wall, which has a structure of refractive elements in the form of a cone or truncated cone in the sense of the invention or a structure of line-shaped refractive elements which run parallel to the light source, may also be parallel to the first wall.

It has been found that an angle of 30 ° to 60 °, in particular 40 °, between the first wall and the second wall gives a good compromise between efficiency, glare, amount of material, luminaire width and height. For larger angles, if you want to retain the space for the light sources, a larger dark area below the light sources and the same light exit surface of the lamp a higher luminaire width. In addition, less light is directed directly from the refractive structure on the second wall to the structure on the first wall and must accordingly be directed by reflections to the light exit surface of the luminaire, which causes higher losses. At smaller angles, the area of the second wall increases. This increases the area on which the refractive structure must be formed and thus the cost.

Advantageously, the parameters of the refractive structures on the first and second walls, in particular the angle between the said straight lines which form or approximate the flanks of the elements in cross section, or the apex angles of a structure with a triangular or triangular cross section and / or the opening angle of a cone or truncated cone in a conical or frusto-conical structure, as well as the refractive index of the materials of the first and second wall optimized such that above a critical angle to the vertical in one or more C-planes or to a perpendicular to the light exit surface in one or more planes perpendicular to the light-emitting surface of the luminaire, which may be in a range of 50 ° to 80 °, the average luminance at the light-emitting surface below 1000 cd / m ² , below 500 cd / m ² or below 200 cd / m ² lies. Depending on the application of the luminaire, however, provision may also be made for the luminance to be greater in one or more planes, possibly even all planes, in the region above said limiting angle and, for example, in this region to be below a limit of the luminance which is in a range between 1000 cd / m ² to 2000 cd / m ² , in particular 1500 cd / m ² to 2000 cd / m ² , without causing a glare to a person who is in the room illuminated by the luminaire comes. In the region below said limiting angle (also referred to as the emitting region), the luminance is generally greater in the entire region than in the region above said limiting angle in said plane (shielding region). For example, the luminance in the emission area may be greater than 1000 cd / m ² . In the case of other luminaires, the luminance in the emission area may be above a value at least in an angle section which lies in a range of, for example, 3000 cd / m ² to 4000 cd / m ² . For a fluorescent lamp of the FQ 24 W type from Osram, a T-16 high-output fluorescent lamp, luminous efficiencies in the range of 5000 cd / m ² can be achieved in the emission range, at least in an angular section.

The invention also provides a luminaire for room lighting, in particular an interior luminaire, which has a cavity with one or more reflective walls, wherein a first wall is translucent at least on a partial area and has a light coupling-out area of the cavity, a second, at least partially translucent Wall extends obliquely to the first wall and with the first wall preferably at an angle less than or equal to 150 °, in particular less than or equal to 90 ° and preferably in a range of 30 ° to 60 °, in particular 40 ° includes, and one of the first wall opposite third wall, which is formed wholly or partially reflecting at least on a partial area, wherein the first wall has a structure of linear refractive elements and the second wall has a structure of linear or conical elements, as described above.

In an embodiment in which the refractive structures are formed linearly on the second wall, they could preferably run parallel to the line-shaped refractive elements on the first wall and in particular parallel to the lamp. However, it can also be provided that the line-shaped structures on the first and second walls do not point in the same direction and in particular perpendicular to each other stand. In this case, according to a preferred embodiment, the refractive structures on the second wall may have the same shape and be subject to the same geometric conditions as the refractive structures on the first wall.

In principle, the refractive structures on the first and second walls may lie on the side facing the cavity or on the side of the wall remote from the cavity.

In particular, the invention can provide that the refractive structures on the second wall lie on the side of the second wall facing the cavity.

This arrangement has several advantages. If the refractive structures on the second wall do not point to the cavity, but to the lamp, especially if the elements of the refractive structure have a triangular cross section with a point angle of 90 °, there is a stop band in which light passes through the total reflection is prevented. Moreover, a refractive structure facing the cavity has less susceptibility to contamination than refractive structures on the outside on which dust and other debris are more easily deposited. Accordingly, no special precautions to protect the refractive structure against soiling, such as by a cover plate over the refractive structure, usually need to be taken.

According to presently preferred embodiments, the refractive structure on the first wall is away from the cavity and is accordingly on the outside of the wall.

The invention can provide that the third wall is translucent, at least in some areas.

In this way, on the opposite side of the first wall, a further light component, for example, for indirect lighting, are coupled out. Such a decoupling can for example take place in that the third wall is continuously transparent and is provided with a refractive structure, similar to that on the first or second wall, which limits the passage of light through the third wall and conditions that on the third wall a Part of the light is reflected back into the cavity. The third wall may also consist wholly or partially of a partially reflective material or have alternating reflective and translucent areas, for example in the form of a perforated plate.

According to the invention it can be provided that the third wall extends beyond the cavity into the region of the light source or the light sources and is formed in the region outside the cavity as a reflector.

Preferably, the reflective portion of the third wall outside the cavity is formed so that at least a portion of the light of one or more light sources is directed to the second wall and thus to the cavity.

According to various embodiments of the invention, the Lichtauskoppelbereich on the first wall at the same time form the light exit surface of the lamp. However, the invention can also provide that the light exit surface of the lamp does not coincide with the Lichtauskoppelbereich the first wall. For example, the first wall of the cavity can rest on a plate which is translucent at least on a partial area, wherein the light coupling-out area of the first wall at least partially overlaps with this translucent area. Ideally, the Lichtauskoppelbereich the first wall is congruent with the translucent region of this plate or it is congruent with a portion of the translucent region of this plate, ie in a projection of the Lichtauskoppelbereich falls in the translucent region of the plate. It can be provided in particular that the plate on which the first wall rests, is translucent.

The invention may provide that one or more light sources, in particular fluorescent lamps, are assigned to one or more reflectors which direct light from the light source to the second wall and thus to the cavity. It can be provided in particular that on opposite sides of a lamp in each case a reflector is provided which directs at least a portion of the light of the light source to the second wall and thus to the cavity.

The invention may provide that the lamp has two opposing cavities which are arranged symmetrically to a median plane.

In a single-lamp embodiment, the center of the lamp is arranged in the said center plane, while in the case of a two-lamp lamp, the lamps are arranged symmetrically to the center plane.

In such a symmetrical embodiment can be provided that the first wall of the two cavities is formed by a single element, for example by a translucent plate which extends over the entire width of the lamp.

According to the invention it can be provided that the first and the second wall are integrally formed with each other.

In this case, the first and second wall together form an open profile, which can be produced for example by extrusion or by setting up the second wall, starting from a plate containing the structures of the first and second wall, for example by hot forming.

The invention may provide that the third wall, which may be formed in particular as a reflector, is formed by a separate component which extends between the free ends of a profile formed by the first and second walls and preferably in the region of these free ends with the first and second wall is connected.

For example, this connection can be effected by latching.

According to the invention it can be provided that the cavity is formed by a closed extrusion profile containing the first, second and third wall.

In this case, the reflection properties of the third wall can be achieved for example by refractive structures on the third wall or by lining by a reflective film. Another way to make the third wall reflective, is to inject in the profile of a reflector, which may for example consist of steel, Teflon or aluminum. Another way to impart reflective properties to the third wall is to provide it with a reflective coating. For example, this third wall may be colored white on the side facing the cavity. Furthermore, extrusion methods can also be used for producing a reflective third wall, in which the extruded material has different properties in different areas. With the aid of such a method, therefore, it is possible, for example, to produce a closed extrusion profile in which the first and second walls are made of a clear, transparent material and the third wall is made of a material which is intrinsically reflective and, for example, may be colored white.

The invention can provide in particular in embodiments in which the cavity is formed wholly or partly by a profile part, provide that the cavity is closed at the front sides by patch caps, said caps preferably reflective on their side facing the cavity, in particular mirrored, formed could be.

The luminaire according to the invention is preferably used as an interior light, in particular as a VDU workplace luminaire. It can be designed, for example, as a suspended pendant luminaire, surface-mounted luminaire, recessed luminaire or floor lamp.

The invention is based on the general concept of using more homogeneous structures to produce the shielding on the light coupling side, which are easier to manufacture and in which the influence of imperfections in the edge regions is less. According to a first embodiment, this is achieved in that the refractive structures on the light coupling side also extend parallel to the lamp axis and thus over a greater distance. It has surprisingly been found that even with such an orientation with a suitable choice of the angle at the free end of the refractive structures shielding the lamp can be achieved in a plane parallel to the refractive structures. According to another embodiment, this is realized in that a plurality of small structures, namely prism cones are provided, each of which has the desired light-directing function and a small size compared to the dimensions of the Lichteinkoppelfläche, so that it is less imperfections of an individual structural element ,

Fig. 1

zeigt in einer schematischen Darstellung ein erstes Ausführungsbeispiel einer erfindungsgemäßen Leuchte,

Fig. 2

illustriert mit Bezug auf die erste Wand eine lichtbrechende Struktur, wie sie an der

-

ersten oder zweiten Wand vorgesehen sein kann.

Fig. 3a und 3b

illustrieren eine lichtbrechende Struktur, wie sie an der zweiten Wand bei einer besonderen Ausführungsform der Erfindung vorgesehen sein kann.

Fig. 4

zeigt eine erste Möglichkeit der Ausbildung des Hohlraums,

Fig. 5

zeigt eine zweite Möglichkeit der Ausbildung eines Hohlraums,

Fig. 6

illustriert den Abschluß des Hohlraums an den Stirnseiten,

Fig. 7

illustriert eine zweite Ausführungsform einer erfindungsgemäßen Leuchte,

Fig. 8

illustriert eine dritte Ausführungsform einer erfindungsgemäßen Leuchte,

Fig. 9

illustriert eine vierte Ausführungsform einer erfindungsgemäßen Leuchte,

Fig. 10

illustriert eine fünfte Ausführungsform einer erfindungsgemäßen Leuchte und

Fig. 11

illustriert eine sechste Ausführungsform einer erfindungsgemäßen Leuchte.

The invention will be explained in more detail below with reference to the accompanying drawings.

Fig. 1

shows a schematic representation of a first embodiment of a lamp according to the invention,

Fig. 2

illustrates, with respect to the first wall, a refractive structure as shown in FIG

-

first or second wall can be provided.

Fig. 3a and 3b

illustrate a refractive structure as may be provided on the second wall in a particular embodiment of the invention.

Fig. 4

shows a first possibility of the formation of the cavity,

Fig. 5

shows a second possibility of forming a cavity,

Fig. 6

illustrates the completion of the cavity at the end faces,

Fig. 7

illustrates a second embodiment of a lamp according to the invention,

Fig. 8

illustrates a third embodiment of a luminaire according to the invention,

Fig. 9

illustrates a fourth embodiment of a luminaire according to the invention,

Fig. 10

illustrates a fifth embodiment of a lamp according to the invention and

Fig. 11

illustrates a sixth embodiment of a luminaire according to the invention.

The light shown in Fig. 1 only schematically with the essential optical components is symmetrical with respect to a median plane M and has two straight rod-shaped lamps 3, for example fluorescent lamps, and two cavities 5, in each of the lamps 3 via a translucent wall 7, which forms a light entry surface for the cavity 5. Light is coupled. Light is coupled out of the cavities 5 in each case by a transparent plate 9, which in each case is opposite a reflector 11, which connects the free end of the translucent plate 7 to the free end of the translucent plate 9. Above and below the lamps 3 reflectors 13 and 14 are arranged, which have the task to redirect the light of the lamps 3 to the plates 7, via which the light is coupled into the respective cavity 5.

According to a possible embodiment, the plates 7 and 9 consist of acrylic glass (for example polymethyl methacrylate) and have over their entire surface a structure of parallel line-shaped prisms 15 (not shown in FIG. 1) whose longitudinal axes are parallel to the axes of the lamps 3 and having a triangular shape in a cross section perpendicular to its longitudinal direction, as shown in the schematic perspective view of Fig. 2 for the plate 9. In the embodiment shown in Fig. 1 of the lamp, the angle w between the two flanks of the triangular cross-section (see Fig. 2) is in each case 116 °. At the corresponding prisms on the plate 7, this angle is 90 °. The prisms on the plate 7 face toward the cavity 5, respectively, while the prisms on the plate 9 face outward. The plate 7 is inclined to the plate 9 at an angle of about 40 °.

The prisms 15 can be produced for example by extrusion or injection compression.

FIGS. 3a and 3b illustrate an alternative prismatic structure which, according to an embodiment of the invention, may be provided on the translucent wall 7. FIG. 3 a shows a schematic side view of the region of a single element 16 of this structure. This element 16 is generated from a circular cone, which is cut off in the region of its base 17 laterally in the form of a hexagon, so that on the side of this circular cone flat surfaces 18 are formed, which extend parallel to the cone axis K and perpendicular to the base 17 and the side opposite the base 17 have a curved boundary line 19 which defines the lower end of the element 16 remote from the tip. The cone axis K simultaneously forms the axis of symmetry of the hexagon formed by the surfaces 18. This shape of a circular cone cut off in the base region makes it possible to form a refractive structure, as shown in a schematic plan view in FIG. 3b. The elements 16 are arranged in a honeycomb-shaped hexagonal structure without a gap to each other. In Fig. 3b, one recognizes the boundary lines 19 between the individual elements 16, which form a hexagonal area-filling pattern. The apex of the elements 16 and the conical surface extending downwards from the apex of the cone are not shown in FIG. 3b. The diameter at the lower end of the elements 16 measured between opposite corners of the hexagon formed by the boundary lines 19 is 2 mm. However, in the embodiment shown in FIG. 3b, it is not the case that is basically possible, but very expensive, that each element is designed as a truncated circular cone with a hexagonal base 17, as shown in FIG. 3a. Rather, the plate, which forms the translucent wall 7, forms the common basis for all elements. From this plate are each the (approximately) circularly tapered elements 16 which adjoin one another along the boundary lines 19, the boundary lines 19 between two such elements in plan view, viewed parallel to the axis K, being straight and bent in a cross section perpendicular to the plate and parallel to the boundary line, the curvature in this cross section corresponds to the boundary line of the side 18 obtained when cutting a truncated cone with a straight plane (see Fig. 3a). The opening angle of the circular cone at the apex is in this embodiment 110 °. As mentioned above, instead of the elements 16 shown in FIG. 3a, it would also be possible to use elements in the form of a six-sided pyramid, which are arranged in a honeycomb-shaped arrangement, as shown in FIG. 3b. Likewise, one could also use a form of the elements 16 for an arrangement according to FIG. 3b, which is generated from a cone other than a circular cone, which is cut off laterally in the region of the base in the form of a hexagon, so that hexagonal surfaces 18, as shown in FIG Fig. 3a are shown formed.

Fig. 4 illustrates a first way to realize a body with the cavity. In the variant illustrated in Fig. 4, the three walls 7, 9 and 11 form walls of a closed profile which is extruded together with the prisms 15. It can be seen in Fig. 4, that the prisms 15 are directed to the plate 7 inwardly and the prisms 15 on the plate 9 to the outside. The different angles w (90 ° or 116 °) are also shown in Fig. 4 for explanation. The wall 11 may be lined with a reflective foil (not shown) on the side facing the cavity 5 to create reflective properties.

Fig. 5 illustrates a second way of realization of the cavity. In this embodiment, the sides 7 and 9 form an angled open profile, in which the wall 7 with the wall 9 forms an angle of 40 °. The wall 11 is formed as a separate part, which is connected via a hook connection 20 at both ends to the respective free end of the walls 7 and 9. The walls 7 and 9 are provided with prisms in the same manner as in the variant shown in FIG. Furthermore, it can be seen in Fig. 5 that the wall 11 is deposited on the cavity 5 side facing with a reflective film 22.

Fig. 6 illustrates how from the hollow profile of Fig. 4 or 5, a hollow light guide is formed. This is done by closing the open sides of the profile with an end wall 24 which is reflective on its inwardly facing side.

Fig. 7 shows a second embodiment of a lamp according to the invention, in which the same or equivalent components with the same reference numerals as in Fig. 1 are designated. In this embodiment, the luminaire is single-lamp with a single lamp 3, the center of which lies in the median plane M. In the embodiment of Fig. 7, the two cavities 5 by two inclined translucent walls 7, a continuous translucent plate 30, which forms the Lichtauskoppelbereich of the cavity for the two cavities respectively instead of the individual plates 9 according to the embodiment of FIG a reflector 32 spanning the entire arrangement is formed, which assumes the function of the two walls 11 and of the reflector 13 in the embodiment of FIG. This arrangement is taken up in total in an extruded profile 34, in which the plate 30 is held by a groove 36 and the reflector 32 by a latching connection 38. The bottom of the profile 34, on which the plate 30 rests, is unstructured both on the side facing the plate 30 and on the opposite side and forms the light exit surface of the luminaire. At the two erected side walls 40 prism structures 42 are respectively formed on the inside. The walls 7 are, as in the embodiment of Fig. 1, on the side facing the cavity 5 each provided with triangular prisms 15 having a point angle w of 90 °, while the plate 30 on the side remote from the cavity side with line-shaped prisms, as shown in Fig. 2, is provided, which have a point angle w of 116 °. For reasons of easier production, these prisms are also provided in the area below the lamp 3, but are covered by the reflector 14.

The profile 34 is connected via a latching connection 50 with a conventional housing part 52, which accommodates various electrical components, including a ballast 54. In this arrangement, optical and electrical components are largely separated. In particular, by removing the entire profile 34 after releasing the latching connection 50, the electrical components in the housing 52 can be accessed directly. Conversely, the optical properties of the luminaire can be easily changed by attaching a profile 34 of the same dimensions, in which optical components with other photometric properties are accommodated, to the housing part 52. This makes it possible to provide luminaires with different optical properties not only different luminaires with the same housing part, but in particular to use a single housing part 52 for different luminaires, in which the electrical components, such as the ballast 54, are already pre-installed. This is a manufacturing advantage. According to a likewise possible implementation of the embodiment of Fig. 7, the reflector 32 and the lamp 3 with the associated lamp sockets (not shown) connected to the housing part 52, so that when removing the profile 34, the plate 30, the walls 7 and Reflector 14 are removed and the lamp 3, which remains at the housing part 52, is exposed. The reflector 32 may be releasably connected to the housing part 52 in a suitable manner, so that by removing the reflector 32 then on electrical components, such as the ballast 54, can be accessed.

The embodiment of FIG. 8 largely corresponds to the embodiment of FIG. 7. In this embodiment, however, the profile 34 is provided on its underside with prisms 15 which, like the walls 9 and the plate 30 in the embodiment of FIG. are provided on the outwardly facing side and have a point angle w of 116 °. Instead of the separate walls 7 of the preceding embodiments, a V-shaped profile 60 made of a translucent material is provided for the light coupling into the cavities 5, which has two legs 62, respectively on the side facing the cavity 5 have line-shaped prisms 15, as shown in Fig. 2, which are parallel to the lamp axis extend and have a point angle w of 90 °. The two legs 62 are connected to each other by an intermediate portion 64, are formed on the projections 66, behind which the reflector 14 is latched. In this embodiment, the reflector 32 is arranged higher with respect to the housing part 52 and the bottom of the profile 34, so that light, which is irradiated into the cavity 5, incident on the translucent side walls 40 of the profile 34. The prisms 42 provided there can be designed so that they direct a proportion of luminous flux laterally to the ceiling or in another desired area. A comparison of Figs. 7 and 8 shows that the same profile 34 can be used for the realization of lights regardless of whether they give off a luminous flux component or not. Furthermore, it can be seen that depending on the position and shape of the reflector, not only a lateral luminous flux through the prisms 42 is made possible or prevented, but also by the position of the lateral edge of the reflector of this proportion of luminous flux can be controlled. For example, the lateral edge of the reflector 32 could lie between the two positions shown in FIGS. 7 and 8 so that only part of the side wall 40 of the profile 34 is incident with light which has been coupled into the cavity. In the embodiment of FIG. 8, in particular it can also be provided that the reflector 32 is connected to the housing part 52 in a suitable manner, for example by latching in the edge regions, as has been explained above.

Fig. 9 shows a further embodiment of a lamp according to the invention, which is designed as a two-lamp pendant lamp. Again, the same or equivalent parts are again denoted by the same reference numerals as in the preceding embodiments. In this luminaire, two extrusion profiles 70 are arranged on both sides of a middle part 71. Each of the two hollow profiles has a light exit wall 72, a light entry wall 74 and a reflective wall 76, wherein the walls 72 and 74 enclose an angle of 40 ° with each other. The walls 72 and 74 are each provided with line-shaped parallel prisms 15 on their outer sides, each extending parallel to the lamp axis and on the wall 72 have a point angle w of 116 ° and at the light entrance side 74 a point angle w of 90 °. The wall 76 is backed by a reflective film 78.

Between the central part 71 and the hollow profiles 70 is in each case a lamp 3, which is associated with a reflector 80 which is located on the side facing away from the hollow profile 70 side of the lamp 3 and at its lower end to those formed by the walls 72 and 74 Tip of the hollow profile 70 connects. On the one hand, the reflectors 80 have the task of reflecting light of the lamps 3 to the light entry wall 74. On the other hand, they also have the task, in particular in their upper part of the light of the lamp 3 to the hollow profile 70 over to reflect upward. The proportion of light reflected in this way can be used for indirect illumination.

The width b of the hollow profile 70 may for example be 130 mm and the height h of the hollow profile may be, for example, 36 mm, wherein the entire luminaire may have a width B of about 330 mm.

10 and 11 show asymmetrical embodiments of a luminaire according to the invention. These embodiments have a cavity 5, which is formed by a covered profile. The body having the cavity is realized in a similar manner as shown in Fig. 5. Corresponding parts are provided with the same reference numerals as in FIG. 5. More precisely, the light entry wall 7 and the light exit wall 9 are formed by an angled profile 85, which, however, unlike the profile of FIG. 5, has an angle of 90 ° between the wall 7 and the wall 9. Both the wall 7 and the wall 9 are provided with prisms as previously mentioned with reference to Fig. 7 and illustrated in Fig. 2, that is, line-shaped prisms having a triangular cross section extending parallel to the lamp axis, and on the wall 7 have a point angle of 90 ° and on the wall 9 have a point angle of 116 °. Notwithstanding the embodiment of FIG. 5, however, the prisms on the wall 7 to the outside, to the lamp out. This is advantageous when the profile 85 is made from a flat plate by hot forming, since then only one side of the original plate needs to be machined to make the prisms 15. The profile 85 is covered by a reflective wall 11, which is connected via hook connections 20 to the wall 7 and 9, respectively at its free end. Outside the cavity 5 is in the vicinity of the wall 7 a Lamp 3 is arranged, which couples via the wall 7 light into the cavity 5. On the side remote from the hollow profile 5 side is in each case a reflector 90 and 92. The reflector 90 shown in Fig. 9 is open at the top and serves a portion of the light emitted by the lamp up to the hollow profile over to the indirect To give off light emission. At the same time he leads around the lamp 3 and connects at its lower end to the hollow profile. In the lamp-near region, this reflector is formed so that it reflects a part of the light to the wall 7. For this purpose, the reflector below the lamp 3 may have a kink 94.

The reflector 92 is bird-wing-like with a tip 96 near and above the lamp and open both up and down. In this case, by reflection on the upper branch 98a of the reflector 92 light is emitted upwards for indirect illumination, while by reflection at the lower branch 98b, a direct proportion of light is emitted downwards. In both cases, electrical components, such as a ballast 100, may be attached to a suitable support structure 102, 104, respectively.

Numerous modifications and variations of the invention can be realized. For example, the embodiments shown as twin-lamp can also be designed as a single lamp and vice versa. While in the embodiments shown in the drawings, the prismatic structures on the walls 7, 62 and 74 are parallel to the lamp axis, according to another embodiment may also be provided that they extend perpendicular to the lamp axis. In this case they preferably have the same apex angle w as the prisms at the bottom, namely 116 °. Alternatively it can be provided that, instead of line-shaped prisms on the light entry walls 6, 62 or 74, conical or frustoconical prisms are provided, the flanks of which may have an opening angle of 100 ° to 128 ° in particular 110 ° in a cross section through the axis of symmetry. These conical or frusto-conical prisms can be arranged hexagonally, for example. A luminaire with asymmetrical emission characteristics does not necessarily have a single cavity according to the invention exhibit. In particular, it can also be provided that in an embodiment with two opposing cavities, the cavities 5 are not arranged symmetrically to each other and / or have a different shape, so that they are no longer mirror images of each other. Additionally or alternatively it can also be provided that the lamp 3 is not arranged symmetrically to the center plane in a monochromatic embodiment or the lamps are not arranged symmetrically to each other in a multi-lamp embodiment and / or the reflectors associated with the lamps, for example the reflectors 13th or 14 are not symmetrical to the median plane M and / or arranged.

The features of the invention disclosed in the description, the claims and the drawings may be essential both individually and in any combination for the realization of the invention in its various embodiments.

LIST OF REFERENCE NUMBERS

3

lamp

5

cavity

7

translucent plate

9

translucent plate

11

reflector

13

reflector

14

reflector

15

prism

16

refractive element

17

Base of the refractive element

18

flat surface

19

boundary line

20

hook connection

22

reflective foil

24

bulkhead

30

translucent plate

32

reflector

34

extruded profile

36

groove

38

locking connection

40

Side wall

42

prismatic structure

50

locking connection

52

housing part

54

ballast

60

V-shaped profile

62

leg

64

intermediate section

66

head Start

70

extrusion profile

71

midsection

72

Light exit wall

74

Light entry wall

76

reflective wall

78

reflective foil

80

reflector

85

profile

90

reflector

92

reflector

94

kink

96

top

98a

upper branch of the reflector

98b

lower branch of the reflector

100

ballast

102

supporting structure

104

supporting structure

K

cone axis

M

midplane

Claims (14)

Luminaire for room lighting, in particular interior lighting, having a cavity (5) with one or more at least partially reflecting walls (11; 32; 76) having a first wall (9; 30; 72) which is translucent at least over a partial area and has a light outcoupling region of a cavity and in the light outcoupling region has a structure of line-shaped refractive elements (15) at least on one side, a second, at least partially translucent wall (7; 62; 74) and a third wall opposite the first wall (11; 32; 76), which is formed completely or partially reflecting at least on a partial area,
and at least one line-shaped light source (3) arranged outside the cavity (5) so that light from these light sources is coupled into the cavity (5) via the second wall (7; 62; 74) and via the light extraction region of the first one Wall (11; 32; 76) is decoupled from the cavity (5),
characterized in that the line-shaped refractive structures on the first wall (11; 32; 76) are parallel to the light source and have a tapered cross-section in a plane perpendicular to the line defining them, the angle (w) being between two straight lines forming the flanks of the cross-section or approximating the flanks of the cross-section is in a range of 100 ° to 130 °, while the second wall (7; 62; 72) in the translucent region over which light the Lamps (3) is coupled into the cavity (5), a structure of line-shaped refractive elements (15) which extend parallel to the light source (3) and in a cross section in a plane perpendicular to the line defining it, a tapered shape with the angle (w) between two straight lines which form the flanks of the cross section or approximate the flanks of the cross section iner than the corresponding angle between the corresponding lines for the elements of the structures on the first wall. Luminaire according to claim 1, characterized in that the angle between the straight lines forming or approximating said edges of the cross-section of the elements of the structure of line-shaped refractive elements (15) of the second wall is in a range of 80 ° to 100 ° , Luminaire according to claim 1 or 2, characterized in that the refractive structures on the first (9; 30; 72) and second walls (7; 62; 74) have a triangular shape in a cross section perpendicular to the line defining them, the angle (w) enclosed by the two legs at the free end of the structures for the structures on the first wall (9; 30; 72) in a range of 100 ° to 130 ° and for the structures on the second wall (7; 62, 74) is in a range of 80 ° to 100 °. Lighting for room lighting, in particular interior lighting, having a cavity (5) with one or more at least partially reflecting walls, the cavity having a first wall (9; 30; 72) which is transparent at least on a partial area and a light coupling-out area of the cavity (5 ) and in the Lichtauskoppelbereich on at least one side has a structure of linear refractive elements (15), a second, at least partially translucent wall (7; 62; 74) and a first wall opposite the third wall (11; 32; 76) which is formed wholly or partially reflecting at least on a partial area,
and at least one line-shaped light source (3) arranged outside the cavity (5) so that light from the light source (3) is coupled into the cavity via the second wall (7; 62; 74) and via the light extraction region of the first one Wall (9; 30; 72) is coupled out of the cavity (5), characterized in that the second wall (7; 62; 74) in the transparent area has a structure of refractive elements each having the shape of a cone or a cone Have truncated cone. Luminaire according to claim 4, characterized in that the cone or a cone, which results from a continuation of said truncated cone, at its tip has an opening angle of 100 ° to 128 °. Luminaire according to claim 4 or 5, characterized in that the cones or truncated cones are arranged hexagonally. Luminaire according to one of claims 1 to 6, characterized in that the second wall (7; 62; 74) encloses an angle in the range of 0 ° to 150 ° with the first wall (9; 30; 72). Luminaire according to one of claims 1 to 7, characterized in that the refractive structures on the second wall (7; 62; 74) lie on the side of the second wall facing the cavity (5). Luminaire according to one of claims 1 to 8, characterized in that the third wall (11; 32; 76) is translucent at least in some areas. Luminaire according to one of claims 1 to 9, characterized in that the third wall (32) extends beyond the cavity (5) into the region of the light source (s) (3) and in the region outside the cavity (5). is designed as a reflector. Luminaire according to one of claims 1 to 10, characterized in that it comprises two mutually opposite cavities (5) which are arranged symmetrically to a median plane (M). Luminaire according to one of claims 1 to 11, characterized in that the first (9; 72) and the second wall (7; 74) are integrally formed with one another. Luminaire according to claim 12, characterized in that the third wall (11) is formed by a separate component which extends between the free ends of a profile formed by the first (9) and second wall (7) and with the first and second Wall is connected. Luminaire according to one of claims 1 to 12, characterized in that the cavity (5) is formed by a closed extrusion profile containing the first (9), second (7) and third wall (11).

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